DASH is the preferred adaptive streaming format with HEVC as the preferred video codec.When encoding in Dolby Digital Plus, the following bit rates are recommended: Stereo and 5.1 content will natively decode on devices while 7.1 content will passthrough. Maximum compatibility with device end points.Note: Roku Ultra 4660X cannot decode Dolby Digital (AC3).
Roku recommends encoding in Dolby Digital Plus instead of Dolby Digital. With the Roku Ultra, Dolby Audio is natively integrated. See Content Meta-Data for more information. Several content meta-data properties are also available for configuring streaming performance: Some customers will have low bit rate connections around 1Mbps or experience intermittent network load that causes drops below Roku recommended network speeds.Roku recommends the user have at least a 1.5Mbps connection.Roku recommends encoding a low bit rate stream around 400Kbps.
If content contains a surround sound track, AAC 2-channel stereo should be provided as a backup audio track. In some cases, lower and higher bit rates have been used, but this frequently results in a bad quality, or limits the numbers of users that can view those encodings. This provides a good balance between quality and support for a wide number of users. For USB playback, we recommend that you stay under 8.0 Mbps. Encoding Guidelinesįor typical streaming video applications, we recommend a range of about 400 Kbps to about 4.0Mbps. Roku Ultra supports the latest Dolby technologies such as Dolby Atmos and System Sound Mixing (MS12). Roku TVs, Roku 4, and Roku Ultra set-top-boxes support multichannel decode to PCM stereo.Ģ Roku TVs and Roku Ultra can decode AC3 and E-AC3, except for Roku Ultra 4660X which cannot decode AC3. All other Roku devices will do passthrough to the receiving device. Note: To discover the supported audio decoders for a Roku device, use ifDeviceInfo.ġ Multichannel AAC is not supported on all Roku models. We strongly recommend that content that is available with multichannel audio (i.e., 5.1, 7.1 channels) be made available in Dolby Digital Plus (E-AC3) as the preferred multichannel format for streaming on our Dolby Digital Plus enabled devices.
Roku devices support the following audio file types: The recommended segment size is < 10 seconds for VOD and < 5 seconds for live content, and the segment size should be constant.ħ Only supported on HDR10 capable Roku devices. Film content is generally 23.976 FPS, while video content is generally at 29.97.ĥ All segments should start with an IDR frame and align across all bit rate variants. For example, a 1.66 aspect ratio source is encoded as a 720x432 video and displayed as letterboxed for a 4:3 display.ģ This is the StreamFormat parameter of the Content MetaData.Ĥ The frame rate used for encoding depends on the source material.
Content should always be encoded at full width, and the height is adjusted. For more device specifications, see Roku Models and Features.ġ Only supported on Roku 4K capable devices.Ģ The dimensions vary on a title-by-title basis depending on the source material and the target aspect ratio for the encoding (such as 4:3 or 16:9).